Dinner, a moveable feast
Dinner originally referred to the first meal of a two-meal day, a heavy meal occurring about noon, which broke the night’s fast in the new day. The word “dinner” comes from the French word diner, “the main meal of the day” from Old French disner (ca 1300).
The standard schedule for centuries was breakfast as the first meal and dinner at noon with a light supper at evening due to an early rise to the day (for the peasants, middle class workers and even royals) and with only oil or candlelight for the evening, it was always early to bed usually at dusk. However, having dinner at noon was sometimes shifted around or delayed due to work. Thus it would take place later in the afternoon around four or five.
With capitalism, colonialism and then the industrial revolution came economic growth for the middle class. People had more money to buy more goods, including lamps and candles. This allowed them to stay up later at night and the dinner hour was pushed ahead to four or five in the afternoon or even later. In the late 1700s and the 1900s people began to work further from home and the mid-day meal had to become something light, thus lunch was introduced; the main meal called dinner was pushed to the evening hours after work.